As long as your garage has the wall vents on the bottom (as most of my California houses did), then it should be fine. Any gas vapors that vent from the Justrite cans will be able to escape from the garage. Also consider whether your garage sits below any other living space (i.e., first-floor garage sits below second-floor bedrooms), as that can cause some problems if the gasoline accelerates a fire.

There may be some other NFPA codes and recommendations (which I think includes not storing gasoline in any part of the actual house, unless it’s a detached building), but heeding the above paragraph would at least mitigate most of the risks.